The invention relates to a mooring device comprising a body provided at a distance above the bottom of the body of water and by means of connecting means having a substantially fixed location with respect to said bottom of the body of water, which body may be a tower placed upon the water bottom, a column swingably connected by its lower end to the water bottom and having buoyancy or a buoy anchored by means of chains, which body has been provided with a support rotatable about a vertical axis which carries swingably about a horizontal axis a weight loaded construction which has been connected to a connecting member which can be loaded at least in tension and which can be attached or has been attached respectively to a floating device such as a vessel.
Such a mooring device is known from e.g. the French patent specification No. 2,420,475 or the European patent application No. 0 105 976. Mooring devices of the known type function like a spring present between the floating device and the body, which spring with increasing load becomes more rigid.
With mooring devices one has to deal with the so called "main forces" resulting from the forces exerted by wind and current on the vessel as well as from forces resulting from the waves. Said forces, depending on their magnitude, cause a certain displacement of the floating device away from the body to which the device has been moored.
Wave forces, however, also cause movements, e.g. a slow movement with low frequency upon which are superimposed movements of high frequency which are related to the wave frequency. The slow movements are dependent on the own frequency of the floating device.
Said movements make it necessary that the floating device, such as a tanker, under the occurring loads resulting from wind, currents and waves remain capable of performing movements.
The known mooring device has the disadvantage that with an increase of the load the action of the spring becomes more rigid and therewith the freedom becomes restricted to perform the movements. The floating device very often is a tanker having such a mass that it will move at any rate under the influence of the occurring forces and this has the result that the connecting members and parts of the mooring device become overloaded and thus damaged.